Pump adjusting means



June 13, 1967 E. E. SCHROEDER 3,324,800

PUMP ADJUSTING MEANS Filed Aug. 1, 1966 9 WW E m 7 I6 2 P BY 7 I 24 um i 2 22 i 28 29 E 3 1 United States Patent Wis.

Filed Aug. 1, 1966, Ser. No. 569,138 3 Claims. (Cl. 103-414) This invention relates generally to pumps and more particularly to an improved means for adjusting the clearance between the pump impeller and the wear plate.

In most pumps, a wear plate is provided between the impeller and the pump casing. The impeller and the wear plate have complementary surfaces between which is defined a running clearance. This running clearance is to prohibit an excessive amount of fluid from bypassing the impeller blades. Some fluid does, however, pass through this running clearance. If the material being pumped includes abrasive particles, the running clearance is enlarged due to wear on the wear plate surface. It is therefore necessary to periodically adjust this running clearance to compensate for this wear.

It is therefore the general object of this invention to provide a pump with an improved means for adjusting the wear plate.

A more specific object of this invention is to provide a simple threaded means for moving the wear plate to adjust the running clearance between the pump impeller and the pump wear plate.

These and other objects of the subject invention will become more fully apparent as the following description is read in light of the attached drawing wherein a partial cross sectional elevation of a pump constructed in accordance with the invention is shown.

Referring to the drawing, the pump casing is generally designated 5. An inlet 6 is provided through one side wall 7 of the pump casing. An outlet 8 is provided in the conventional manner for centrifugal pumps.

A shaft 9 extends through the rear of the pump casing and terminates in a pumping chamber 11 defined by the pump casing. The pump impeller 12, shown herein for purposes of illustration only is of the closed type having a front shroud plate 13 and a rear shroud plate 14, with a plurality of blades 16 connected therebetween. The pump impeller is positioned in the pumping chamber and may be connected to drive shaft 9 in any conventional manner. For purposes of illustration, the impeller shown herein is provided with an internally threaded hub 17. This internally threated hub is received on a threaded end of the shaft.

The front portion of the shroud late 13 has an annular surface 18 formed thereon. Positioned between this surface 18 and the side wall 7 of the pump casing is an annular wear plate generally designated 19. This wear plate is also provided with an annular surface 21 complementary to the impeller surface 18. These two surfaces define therebetween a running clearance 22 to prohibit excessive flow of fluid from the inlet 6 between the front shroud plate 13 of the impeller and the annular wear plate 19. It should be understood that the pump impeller may be of the open type without departing from the spirit of the invention. With an open impeller the configuration of the wear plate would conform to the shape of the front surface of the impeller blades. An opening 23 is provided through the wear plate 19 in alignment with the pump inlet 6.

The wear plate is initially adjusted to provide a minimum clearance. However, as wear takes place, further adjustment is necessary. To this end the Wear plate 19 is provided with preferably three equally spaced internally threaded bores 24. These bores are axially aligned with an equal number of openings 26 provided through the Patented June 13, 1967 casing side wall 7. An adjusting means generally designated 27 or stud extends through the opening and into threaded bores. The portion of the stud extending into the threaded bore has an oversized threaded portion 28. Threaded portion 28 has a diameter larger than the diameter of the opening 26 thereby providing a shoulder 29 engaging the inner surface of the side walls. The portion of the stud extending Without the casing also has a threaded portion 31 thereon. The end 32 of the stud may be formed in a parallel flat surface to permit easy turning of the stud. A washer 33 is provided about the threaded portion 31 and a nut 34 is turned thereon. For sealing purposes an O-ring may be provided about the threaded portion 31 to block the flow of fluid through the openings 26 through the casing side wall 7.

When it is desired to adjust the position of the wear plate 19, the nut 34 is loosened on the threads 31. The stud is then turned in a counterclockwise direction causing the shoulder 29 to bear against the inner surface of the side wall 7. This causes the rear plate 19 to move to the left thereby decreasing the running clearance 22.

From the above description it can be seen that a very simplified and inexpensive means has been provided for adjusting a wear plate for pumps.

Although only one embodiment of the subject invention has been herein shown and described, it will be apparent after reading this description that other embodiments are possible Without departing from the spirit of the invention and it is intended that all such embodiments as come within a reasonable interpretation of the appended claims be covered.

The embodiments of the invention in which an exclusive property of privilege is claimed are defined as follows:

1. A pump comprising: a casing defining a pumping chamber having an inlet through a side wall of said casing and an outlet; a shaft adapted to be connected to a source of power and extending through said casing into said chamber; an impeller located within said chamber and connected to said shaft for rotation therewith, a wear plate positioned between said casing side and wall and said impeller and having an opening therethrough aligned with said inlet, said wear plate having a surface complementary to the forward portion of said impeller and forming a running clearance therebetween; walls defining a plurality of openings through said casing side wall; walls defining a plurality of threaded bores in said wear plate aligned with said plurality of openings; adjusting means extending through said openings having a first threaded portion threadably engaging said threaded bore and a second portion extending without said casing; and a shoulder on said adjusting means having a diameter larger than the diameter of said openings and located between said casing side wall and said wear plate to prohibit relative axial movement between said adjusting means and said side wall in one direction whereby rotation of said adjusting means relative to said wear plate causes said shoulder to react against said casing side wall to change the running clearance between said impeller and said wear plate surface.

2. A pump according to claim 1 wherein said second portion of said adjusting means is threaded and further comprising a nut threaded on the second portion of said adjusting means for selective engagement with the outer surface of said side wall to prohibit axial movement in a direction opposite to said one direction.

3. The pump set forth in claim 2 wherein said shoulder is defined by said first threaded portion of said adjusting means.

(References on following page) 3 4 References Cited FOREIGN PATENTS UNITED STATES PATENTS 723,344 1/1932 France. 1,735,754 11/1929 Hargis 103 114 DONLEY J. STOCKING, Primary Examiner.

2,736,265 2/1956 Higgins 5 HENRY RRADUAZO, Examiner, 

1. A PUMP COMPRISING: A CASING DEFINING A PUMPING CHAMBER HAVING AN INLET THROUGH A SIDE WALL OF SAID CASING AND AN OUTLET; A SHAFT ADAPTED TO BE CONNECTED TO A SOURCE OF POWER AND EXTENDING THROUGH SAID CASING INTO SAID CHAMBER; AN IMPELLER LOCATED WITHIN SAID CHAMBER AND CONNECTED TO SAID SHAFT FOR ROTATION THEREWITH, A WEAR PLATE POSITIONED BETWEEN SAID CASING SIDE AND WALL AND SAID IMPELLER AND HAVING AN OPENING THERETHROUGH ALIGNED WITH SAID INLET, SAID WEAR PLATE HAVING A SURFACE COMPLEMENTARY TO THE FORWARD PORTION OF SAID IMPELLER AND FORMING A RUNNING CLEARANCE THEREBETWEEN; WALLS DEFINING A PLURALITY OF OPENINGS THROUGH SAID CASING SIDE WALL; WALLS DEFINING A PLURALITY OF THREADED BORES IN SAID WEAR PLATE ALIGNED WITH SAID PLURALITY OF OPENINGS; ADJUSTING MEANS EXTENDING THROUGH SAID OPENINGS HAVING A FIRST THREADED PORTION THREADABLY ENGAGING SAID THREADED BORE AND A SECOND PORTION EXTENDING WITHOUT SAID CASING; AND A SHOULDER ON SAID ADJUSTING MEANS HAVING A DIAMETER LARGER THAN THE DIAMETER OF SAID OPENINGS AND LOCATED BETWEEN SAID CASING SIDE WALL AND SAID WEAR PLATE TO PROHIBIT RELATIVE AXIAL MOVEMENT BETWEEN SAID ADJUSTING MEANS AND SAID SIDE WALL IN ONE DIRECTION WHEREBY ROTATION OF SAID ADJUSTING MEANS RELATIVE TO SAID WEAR PLATE CAUSES SAID SHOULDER TO REACT AGAINST SAID CASING SIDE WALL TO CHANGE THE RUNNING CLEARANCE BETWEEN SAID IMPELLER AND SAID WEAR PLATE SURFACE. 